What is the game called where you try to avoid other players lines Each of the lines are colored and you use the arrow keys to turn?

The game you're referring to is likely "Slither.io" or a similar variant. In this multiplayer online game, players control a snake-like character that leaves a trail behind, and the objective is to avoid running into other players' lines while trying to make them collide with yours. Players navigate using the arrow keys or touch controls, and the game involves strategy and quick reflexes to grow and survive.